Question

How many moles of O2 will be released if a liter of blood containing 45 g of hemoglobin is transferred

from 60 torr, pH 7.6 to 20 torr, pH 7.2? Hemoglobin has a molecular weight of 68,000

Answer 1

As we can see in the hemoglobin binding curve, at 60 torr and pH 7.6 binding is approximately 100%. At 20 torr and pH 7.2, binding is about 25%. So we can say that about 75% of the oxygen will be released.

We have 45 g of hemoglobin:

45 g of hemoglobin * (1mol / 68000 g) = 6.6176 x 10^-4 moles of hemoglobin.

Each mol of hemoglobin can bind 4 moles of oxygen

6.6176 x 10^-4 moles of hemoglobin * (4 moles of O₂ / 1 mol of hemoglobin) = 0.002647 moles of O₂

75% will be released:

0.002647 * 0.75 = 0.00198 moles of oxygen released.